"Blocks like the one shown above were first cut fromk a vein
by chiseling a groove into a fault in the marble, inserting olive
wood wedges and pouring water on them.
The expansion of the wedges would split the stone along the line of the fault. Single blocks were then hauled on wooden rollers or iron balls to chutes carved from the living stone and greased with soap. Restrained by ropes or slings and resting on beams, a block would be eased down the chute to wating carts.
Michelangelo tells us in a letter of 1518 what happened when a mistake in slinging caused a block to break loose --- "one man had his neck broken and died instantly, and it nearly cost me my life." ...."